With Digital Image Correlation (DIC) on the rise to measure full-field strain and displacement, Instron talks with Advanced Materials & Processes (AM&P) on this optical technique.

“Traditional strain measurement requirements involve characterizing axial strain at one gauge length in the center of the specimen. In some cases, transverse strain is also measured to determine Poisson’s ratio, and strain gauges are used where it is difficult to use traditional extensometers. However, existing strain measurement techniques do not offer enough information about how failures occur, so alternative methods are required. One technique involves using Digital Image Correlation (DIC) to measure full-field strain over the entire material surface. In addition to the strain map produced, virtual strain gauges and extensometers can be placed on the specimen after the test and replayed multiple times. Further, the technique can be used for almost any material; polymers, metals, composites, rubbers, foams, textiles, and other materials have been tested using DIC.”